1. Field of the Invention
The present invention relates to a simulation wheel used in a vehicle testing apparatus for measuring power transmitted from an engine to an axle, and the vehicle testing apparatus.
2. Description of the Related Art
Among vehicle running tests, there is a test for measuring how power is transmitted from an engine to an axle during running.
A chassis dynamometer is often used for performing the vehicle running test. However, when the chassis dynamometer is used, it is necessary to fix a vehicle. Thus, the test is performed with a suspension, a damper or the like not being in operation. In this case, it is not possible to perform the test with the suspension, the damper or the like operating to simulate a state in which an actual vehicle is running.
Thus, in order to perform the test with the suspension, the damper or the like operating as in the state in which the actual vehicle is running, a low inertia dynamometer (referred to as dynamometer below) may be used instead of the chassis dynamometer to perform the running test.
Conventionally, when the running test is performed by using such a dynamometer, the suspension, the damper, and even the brake or the like are removed, and a measurement bearing is attached to an axle to measure the state of power transmission from an engine to the axle. However, it is recently attempted to develop a configuration to measure the state of power transmission from the engine to the axle by use of the bearing without removing the suspension, the damper, the brake or the like. If such a configuration can be developed, it would become possible to accurately perform the test on how the power is transmitted from the engine to the axle while the suspension, the damper or the like remain attached and are further brought into an operating state.
FIG. 1 is a view illustrating an example of the configuration of such a bearing 21.
As shown in FIG. 1, one end of a joint 22 is coupled to a fixed-type bearing 21 to which an axle is coupled and which is fixedly installed on a floor at a measurement location. The other end of the joint 22 is further coupled to an unillustrated dynamometer. With the configuration, the test can be directly performed without bothering to remove a brake BR or the like of a vehicle.
In the configuration, however, both the position and inclination of a rotating center axis of the axle are fixed by the bearing 21, and the movements of a suspension, a damper or the like are restricted. Thus, an axle state during running cannot be recreated.
Furthermore, with the configuration in FIG. 1, it is not possible to perform the test on how the power transmitted to the axle is changed when the influence of a tire operating in conjunction with the suspension and the damper is also taken into consideration.
The present invention provides a simulation wheel capable of simulating an axle state while an actual vehicle is running on a road, and a vehicle testing apparatus capable of performing a test on how a state of power transmitted from an engine to an axle is changed while applying load from a dynamometer by using the simulation wheel.